Chickenpox is a highly contagious infectious disease caused by the Varicella zoster virus; sufferers develop a fleeting itchy rash that can spread throughout the body. The disease can last for up to 14 days and can occur in both children and adults, though the young are particularly vulnerable. Individuals infected with chickenpox can expect to experience a high but tolerable level of discomfort and a fever as the disease works its way through the system. The ailment was once considered to be a “rite of passage” by parents in the U.S. and thought to provide children with greater and improved immunity to other forms of sickness later in life. This view, however, was altered after additional research by scientists demonstrated unexpected dangers associated with the virus. Over time, the fruits of this research have transformed attitudes toward the disease and the utility of seeking preemptive measures against it. A vaccine against chickenpox was originally invented by Michiaki Takahashi, a Japanese doctor and research scientist, in the mid-1960s. Dr. Takahashi began his work to isolate and grow the virus in 1965 and in 1972 began clinical trials with a live but weakened form of the virus that caused the human body to create antibodies. Japan and several other countries began widespread chickenpox vaccination programs in 1974. However, it took over 20 years for the chickenpox vaccine to be approved by the U.S. Food & Drug Administration (FDA), finally earning the U.S. government’s seal of approval for widespread use in 1995. Yet even though the U.S. encouraged the development, adoption, and use of a vaccine against chickenpox to the public. Although the appearance of chickenpox and shingles within one person can be many years apart—generally many decades— the increased risk in developing shingles as a younger adult (30-40 years old rather than 60-70 years old) proved to be enough to convince the medical community that immunization should be preferred to the traditional alternative. Another reason that the chickenpox vaccine was not immediately accepted and used by parents in the U.S. centered on observations made by scientists that the vaccine simply did not last long enough and did not confer a lifetime of immunity. In other words, scientists considered the benefits of the vaccine to be temporary when given to young children. They also feared that it increased the odds that a person could become infected with chickenpox later as a young adult when the rash is more painful and prevalent and can last up to three or four weeks. Hence, allowing young children to develop chickenpox rather than take a vaccine against it was believed to be the “lesser of two evils.” This idea changed over time as booster shots of the vaccine elongated immunity and countered the perceived limits on the strength of the vaccine itself. Today, use of the chickenpox vaccine is common throughout the world. Pediatricians suggest an initial vaccination shot after a child turns one year old, with booster shots recommended after the child turns eight. The vaccine is estimated to be up to 90% effective and has reduced worldwide cases of chickenpox infection to 400,000 cases per year from over 4,000,000 cases before vaccination became widespread. In light of such statistics, most doctors insist that the potential risks of developing shingles outweigh the benefits of avoiding rare complications associated with inoculations. Of course, many parents continue to think of the disease as an innocuous ailment, refusing to take preemptive steps against it. As increasing numbers of students are vaccinated and the virus becomes increasingly rarer, however, even this trend among parents has failed to halt the decline of chickenpox among the most vulnerable populations.

Now answer the questions.

Paragraph 1 Chickenpox is a highly contagious infectious disease caused by the Varicella zoster virus; sufferers develop a fleeting itchy rash that can spread throughout the body. The disease can last for up to 14 days and can occur in both children and adults, though the young are particularly vulnerable. Individuals infected with chickenpox can expect to experience a high but tolerable level of discomfort and a fever as the disease works its way through the system. The ailment was once considered to be a “rite of passage” by parents in the U.S. and thought to provide children with greater and improved immunity to other forms of sickness later in life. This view, however, was altered after additional research by scientists demonstrated unexpected dangers associated with the virus. Over time, the fruits of this research have transformed attitudes toward the disease and the utility of seeking preemptive measures against it.

1. The word tolerable in the passage is closest in meaning to A. sudden B. bearable C. infrequent D. unexpected

2. According to paragraph 1, which of the following is true of the chickenpox virus? A. It leads to a potentially deadly disease in adults. B. It is associated with a possible permanent rash. C. It is easily transmittable by an infected individual. D. It has been virtually eradicated in the modern world.

3. Which of the following best expresses the essential information in the highlighted sentence? Incorrect answer choices change the meaning in important ways or leave out essential information. A. U.S. parents believed that having chickenpox benefited their children. B. U.S. parents believed that chickenpox led to immunity against most sickness. C. U.S. parents wanted to make sure that their children developed chickenpox. D. U.S. parents did not think that other vaccinations were needed after chickenpox.

Paragraph 2 A vaccine against chickenpox was originally invented by Michiaki Takahashi, a Japanese doctor and research scientist, in the mid-1960s. Dr. Takahashi began his work to isolate and grow the virus in 1965 and in 1972 began clinical trials with a live but weakened form of the virus that caused the human body to create antibodies. Japan and several other countries began widespread chickenpox vaccination programs in 1974. However, it took over 20 years for the chickenpox vaccine to be approved by the U.S. Food & Drug Administration (FDA), finally earning the U.S. government’s seal of approval for widespread use in 1995. Yet even though the chickenpox vaccine was available and recommended by the FDA, parents did not immediately choose to vaccinate their children against this disease. Mothers and fathers typically cited the notion that chickenpox did not constitute a serious enough disease against which a person needed to be vaccinated.

4. Which of the following can be inferred from paragraph 2 about the clinical trials for the chickenpox vaccine? A. They took longer than expected. B. They cost a lot of money to complete. C. They took a long time to finish. D. They were ultimately successful.

5. The word notion in the passage is closest in meaning to A. history B. findings C. fact D. belief

Paragraph 3: Strong belief in that view eroded when scientists discovered the link between Varicella zoster, the virus that causes chickenpox, and shingles, a far more serious, harmful, and longer-lasting disease in older adults that impacts the nervous system. They reached the conclusion that Varicella zoster remains dormant inside the body, making it significantly more likely for someone to develop shingles. As a result, the medical community in the the U.S. encouraged the development, adoption, and use of a vaccine against chickenpox to the public. Although the appearance of chickenpox and shingles within one person can be many years apart—generally many decades—the increased risk in developing shingles as a younger adult (30-40 years old rather than 60-70 years old) proved to be enough to convince the medical community that immunization should be preferred to the traditional alternative.

6. According to paragraph 3, which of the following is true of Varicella Zoster? A. It typically attacks adults who are over 60 years old. B. It is linked to a serious disease that occurs more commonly in adults. C. It likely is not a serious enough threat to human health to require a vaccine. D. It is completely eradicated from the body after chickenpox occurs.

Paragraph 4 Another reason that the chickenpox vaccine was not immediately accepted and used by parents in the U.S. centered on observations made by scientists that the vaccine simply did not last long enough and did not confer a lifetime of immunity. In other words, scientists considered the benefits of the vaccine to be temporary when given to young children. They also feared that it increased the odds that a person could become infected

with chickenpox later as a young adult when the rash is more painful and prevalent and can last up to three or four weeks. Hence, allowing young children to develop chickenpox rather than take a vaccine against it was believed to be the “lesser of two evils.” This idea changed over time as booster shots of the vaccine elongated immunity and countered the perceived limits on the strength of the vaccine itself.

7. The word prevalent in the passage is closest in meaning to A. dangerous B. widespread C. infectious D. contaminated

8. The author uses booster shots as an example of A. a scientifically approved medicine to eliminate chickenpox B. a preferred method of chickenpox rash and fever treatment C. a way to increase the effectiveness of the chickenpox vaccine D. a strategy for parents to avoid vaccinating their child altogether

9. The word countered in the passage is closest in meaning to A. affirmed B. refuted C. supported D. defied

10. According to paragraph 4, many parents did not choose the chickenpox vaccine because A. they believed that the virus was weak and not especially harmful B. they thought that scientists did not have enough data to reach a conclusion C. they were unsure about the utility of the vaccine given its expected duration D. they were convinced it was potentially very toxic, particularly for older children

Paragraph 5 Today, use of the chickenpox vaccine is common throughout the world. Pediatricians suggest an initial vaccination shot after a child turns one year old, with booster shots recommended after the child turns eight. The vaccine is estimated to be up to 90% effective and has reduced worldwide cases of chickenpox infection to 400,000 cases per year from over 4,000,000 cases before vaccination became widespread. ■ (A) In light of such statistics, most doctors insist that the potential risks of developing shingles outweigh the benefits of avoiding rare complications associated with inoculations. ■ (B) Of course, many parents continue to think of the disease as an innocuous ailment, refusing to take preemptive steps against it. ■ (C) As increasing numbers of students are vaccinated and the virus becomes increasingly rarer, however, even this trend among parents has failed to halt the decline of chickenpox among the most vulnerable populations. ■ (D)

11. According to paragraph 5, which of the following was true of the rates of chickenpox before the chickenpox vaccine became widely used? A. it was 10 times higher B. it was consistently rising C. it declined over time D. it fluctuated over several decades

The Four Great Kangaroos

Although the kangaroo is Australia’s most famous indigenous species, few people outside of the country know many details about the animal. In fact, there are several different kangaroo species, including the western grey kangaroo, the eastern grey kangaroo, the red kangaroo, and the antilopine kangaroo. Though still bound together by traits characteristic of the genus Macropus, the four different types of kangaroo–also known as the four “Great Kangaroos,” as they are the largest species in the genus–can behave very differently in terms of their native habitats, activities, and migration patterns. The eastern grey kangaroo lives, as its name implies, on the east coast of Australia. Not only is the eastern grey the most common kangaroo, but it is also the quickest, as the fastest recorded kangaroo was a large female traveling at 40 miles per hour. It is by far the most populous kangaroo species; around ten million eastern greys inhabit the continent. To put that in perspective, Australia’s current human population is only 23 million. The eastern grey prefers to inhabit large open areas of grassland, with shrubbery for daytime shelter, as it forages for food at night. Nevertheless, eastern greys have been seen in various climates, including coastal areas, woodlands, subtropical forests, and mountainous regions. The western grey is difficult to distinguish from the eastern grey; for many years, the two were thought to belong to the same species. The western grey is distinguished, in the first place, by its habitat, on the west (rather than the east) coast of Australia. Secondly, it is different from the eastern grey in that it is a very vocal species. Mother western grey kangaroos communicate to their offspring, or joeys, with a series of clicking noises, which eastern grey mothers do not do. Though less adaptable than the eastern grey, the western grey can still be found in a variety of habitats, including grasslands, forests, or woodlands near water. Zoologists believe that the population of western grey kangaroos increased dramatically as Europeans settled in Australia because this led to the creation of more pastures, where members of the species could find their main food source, grass.

Unlike the two species of grey kangaroos, the red kangaroo is found throughout Australia, though there is a concentration of reds in the west corner of New South Wales, in the southeastern part of the country. The red has the ability to store water for periods of time, and so does not need to inhabit the same fertile areas as its grey cousins. Instead, this species can be found in more arid climates, including scrubland and deserts. The species has a remarkable ability to find nutritious food sources even in areas that seem devoid of life. Less social and more nomadic than the grey kangaroos, the red has the distinctions of being the largest of all kangaroos, the largest mammal native to Australia, and the largest living marsupial.

Finally, the antilopine kangaroo breaks the trend among the three greats named for their color, drawing instead from a comparison to the antelope, which zoologists thought the kangaroo resembled with its distinctive appearance. Traveling in packs of up to 30 kangaroos, the antilopine inhabits the northern tropical and western regions of Australia, preferring flat, open lands, though their habitat does sometimes extend to eucalyptus woodlands. Like the eastern gray, the antilopine sleep under the shade of shrubs during the hottest part of the day, grazing during the evenings from approximately an hour after sunset until 8 am. It has the largest range of all the great kangaroo species and is known to travel up to a third of a mile (76 hectares) from its group’s territory. In the wet season, antilopine females outnumber the males by a ratio of two to one; in the dry season, this increases to three to one. Even these four species of kangaroos do not fully represent their genus. Although the most populous are the “great” kangaroos or the largest, there are many other, smaller species (up to 47) found throughout Australia. Like the four greats, these kangaroos are often descriptively named. There are large populations of tree-kangaroos, for example, in wooded areas, as well as various species of rat-kangaroos. If you’re traveling through Australia, keep your eyes open: You never know if you’re actually looking at a kangaroo you never knew existed.

Now answer the questions.

Paragraph 1 Although the kangaroo is Australia’s most famous indigenous species, few people outside of the country know many details about the animal. In fact, there are several different kangaroo species, including the western grey kangaroo, the eastern grey kangaroo, the red kangaroo, and the antilopine kangaroo. Though still bound together by traits characteristic of the genus Macropus, the four different types of kangaroo–also known as the four “Great Kangaroos,” as they are the largest species in the genus–can behave very differently in terms of their native habitats, activities, and migration patterns.

1. The word “indigenous” in paragraph 1 is closest in meaning to A. large B. important C. known D. local

2. The author discusses the term “Great Kangaroos” in paragraph 1 in order to emphasize the kangaroos’ A. prevalence B. importance C. fame D. size

Paragraph 2 The eastern grey kangaroo lives, as its name implies, on the east coast of Australia. Not only is the eastern grey the most common kangaroo, but it is also the quickest, as the fastest recorded kangaroo was a large female traveling at 40 miles per hour. It is by far the most populous kangaroo species; around ten million eastern greys inhabit the continent. To put that in perspective, Australia’s current human population is only 23 million. The eastern grey prefers to inhabit large open areas of grassland, with shrubbery for daytime shelter, as it forages for food at night. Nevertheless, eastern greys have been seen in various climates, including coastal areas, woodlands, subtropical forests, and mountainous regions.

3. According to paragraph 2, the eastern grey kangaroo is different from other species in its A. population size B. preferred habitat C. occupation of varied climates D. distinctly larger body

Paragraph 3 The western grey is difficult to distinguish from the eastern grey; for many years, the two were thought to belong to the same species. The western grey is distinguished, in the first place, by its habitat, on the west (rather than the east) coast of Australia. Secondly, it is different from the eastern grey in that it is a very vocal species. Mother western grey kangaroos communicate to their offspring, or joeys, with a series of clicking noises, which eastern grey mothers do not do. Though less adaptable than the eastern grey, the western grey can still be found in a variety of habitats, including grasslands, forests, or woodlands near water. Zoologists believe that the population of western grey kangaroos increased dramatically as Europeans settled in Australia because this led to the creation of more pastures, where members of the species could find their main food source, grass.

5. It can be inferred from paragraph 3 that A. European settlement in Australia led to a decrease in the numbers of eastern grey kangaroos as farmland took over B. when Europeans settled in Australia, they cultivated the land on their homesteads so that it grew grass C. the increased numbers of western grey kangaroos helped to distinguish them from eastern grey kangaroos D. European settlers did not find the western greys threatening because of the soothing clicking noises the kangaroos made

6. The word “adaptable” in paragraph 3 is closest in meaning to A. flexible B. common C. agile D. mobile

Paragraph 4 Unlike the two species of grey kangaroos, the red kangaroo is found throughout Australia, though there is a concentration of reds in the west corner of New South Wales, in the southeastern part of the country. The red has the ability to store water for periods of time, and so does not need to inhabit the same fertile areas as its grey cousins. Instead, this species can be found in more arid climates, including scrubland and deserts. The species has a remarkable ability to find nutritious food sources even in areas that seem devoid of life. Less social and more nomadic than the grey kangaroos, the red has the distinctions of being the largest of all kangaroos, the largest mammal native to Australia, and the largest living marsupial.

7. Which of the sentences below best expresses the essential information in the highlighted sentence in paragraph 4? Incorrect answer choices change the meaning in important ways or leave out essential information. A. New South Wales, in southeastern Australia, is important as a sanctuary for red kangaroos. B. Red kangaroos are similar to grey kangaroos in most ways, except for where it can be found. C. Grey kangaroos cover a wider area of the country than the red kangaroo, which is only found in the southeast. D. Red kangaroos are different from other species because they inhabit different areas of Australia.

8. According to paragraph 4, red kangaroos are able to be more nomadic than either species of gray kangaroo because of the reds A. can find food in any environment, even when other animals cannot. B. do not need to stay with a tribe, because they live as individuals. C. their larger size allows them to travel far due to their longer stride. D. their ability to retain water lets them live in different climates.

Paragraph 5 Finally, the antilopine kangaroo breaks the trend among the three greats named for their color, drawing instead from a comparison to the antelope, which zoologists thought the kangaroo resembled with its distinctive appearance. Traveling in packs of up to 30 kangaroos, the antilopine inhabits the northern tropical and western regions of Australia, preferring flat, open lands, though their habitat does sometimes extend to eucalyptus woodlands. Like the eastern gray, the antilopine sleep under the shade of shrubs during the hottest part of the day, grazing during the evenings from approximately an hour after sunset until 8 am. It has the largest range of all the great kangaroo species and is known to travel up to a third of a mile (76 hectares) from its group’s territory. In the wet season, antilopine females outnumber the males by a ratio of two to one; in the dry season, this increases to three to one.

10. The author’s discussion of the antilopine kangaroos’ gender balance in paragraph 5 indicates that A. it varies according to the season B. it favors large populations of males C. it is caused by the species’ ability to travel D. antilopine kangaroos thrive in the rain

11. According to paragraph 5, which of the following is NOT a unique feature of the antilopine kangaroo? A. Appearance B. The radius of travel from its pack C. The origin of its name D. Its preferred habitat

Paragraph 6 Even these four species of kangaroos do not fully represent their genus. Although the most populous are the “great” kangaroos or the largest, there are many other, smaller species (up to 47) found throughout Australia. Like the four greats, these kangaroos are often descriptively named. There are large populations of tree-kangaroos, for example, in wooded areas, as well as various species of rat-kangaroos. If you’re traveling through Australia, keep your eyes open: You never know if you’re actually looking at a kangaroo you never knew existed.